Police said Massenburg's shooting may have been a case of mistaken identity. A battle brewing between two violent gangs is what police said possibly lead to the Chicago native being gunned down in a drive-by shooting on a West Carollton street on April 1.

Massenburg's father, Andre Massenburg, said he's thankful someone came forward to begin bringing justice to his son's killer. Andre Massenburg only knows his son was trying to do good when he moved to New Orleans to volunteer with Americorps.

“He enjoyed it, 18 years old, first time away from home, living life, didn't have a care in the world,” Andre Massenburg said.

Police said the neighborhood where he was shot is gang territory occupied by a gang known as the Hot Glocks. A rivalry between Hot Glocks and another gang known as the Mid-City Killers was underway the night Massenburg was killed.

“Joseph went outside to talk on the phone. Some minutes later they heard gunshots, and Joseph was found lying in the street on the sidewalk fighting for his life,” Andre Massenburg said.

Nearly three months after the shooting, police were searching for Emerson, who was identified by a witness.

“It was a little frustrating because we put out Mr. Emerson about five weeks ago, and people don't typically stay wanted that long in this city for murder,” said Detective Nicholas Gernon, of the New Orleans Police Department.

On Thursday night, investigators said they were tipped off to Emerson's location while working a separate murder case. He was arrested at an apartment complex in New Orleans East. Detectives said Emerson tried to escape out of the window of the apartment.

“The important thing is that he is now in jail, he is not going to be able to hurt anybody else, and his co-perpetrators, they know who they are, and they need to know that the community has been stepping forward and has been giving us information,” Gernon said.

Andre Massenburg said the arrest of one man doesn't exactly bring closure, but he does believe his son has received a measure of justice.

“Today is a good day for justice because Mr. Emerson has been captured, so from that perspective, we're happy," said Andre Massenburg.

Andre Massenburg said he's also thankful that someone stood up for his son's justice.

“To that young lady, to that young man that picked up the phone and called the authorities, I say thanks, my wife says, 'Thank you for doing the right thing,'" said Andre Massenburg.

Police said Emerson is suspected of driving the getaway car the night Massenburg was shot. Andre Massenburg's message to Emerson is to cooperate with police as they continue to look for the shooter.

Emerson faces one count of second-degree murder. During the time of his arrest, police also arrested two others on unrelated charges, recovered two weapons and two stolen vehicles.